Mismatch Responses to Speech Contrasts in Preschoolers with and without Developmental Language Disorder

Area of Science:

• Neuroscience
• Developmental Psychology
• Linguistics

Background:

• Understanding the neural basis of speech perception in early childhood is crucial.
• Investigating top-down language effects, where higher-level linguistic knowledge influences sensory processing, is key to characterizing typical and atypical language development.
• Developmental Language Disorder (DLD) affects language acquisition, but its impact on the neural processing of speech is not fully understood.

Purpose of the Study:

• To compare cortical responses to speech stimuli between preschoolers with typical language development (TLD) and those with Developmental Language Disorder (DLD).
• To determine if young children exhibit adult-like top-down modulation of speech perception.
• To explore the relationship between phonological skills and cortical speech discrimination in children.

Main Methods:

• Cortical mismatch responses (MMRs) were measured during passive speech contrast perception in three groups: TLD preschoolers, DLD preschoolers, and adults.
• Phonological skills were assessed in the child groups.
• MMR measures were analyzed for differences between groups and associations with phonological skills.

Main Results:

• Adults showed top-down effects, with enhanced cortical discrimination for lexical stimuli but not non-words.
• No significant differences in MMRs were found between TLD and DLD preschoolers.
• No top-down effects were detected in either preschool group, and no association was found between MMRs and phonological skills, despite lower skills in the DLD group.

Conclusions:

• Top-down language modulations in speech discrimination may not be established in early childhood.
• Preschoolers with DLD do not appear to exhibit cortical speech perception deficits compared to peers with TLD.
• Further research is needed to elucidate the connection between phonological abilities and cortical activity in young children's speech processing.